[exim] Spamassassin + Exim4 high IO Wait

Hi All,

I was hoping to draw from the pool of experience that the exim mailing
list has, as I realise this is a spamassassin or other issue. We are
running exim4.62-4 with Spamassassin 3.1.4-4 and suffering extremely
high IO Wait times on the server whenever spamassassin scans an incoming
email. Exim4 is setup as defaults (spamd running locally on standard
port) so no configuration was changed. Spamassassin has not had any
rules added to it. The server goes from 1-2% wait times spiking to
between 20-90% when spamd is scanning an email, this lasts for a few
seconds and then drops back down to normal. This is a system with raided
SATA drives on a LVG that also serves small SMB shares. It serves around
40 mail users.

I have not had this problem on servers with SCSI drives, or on servers
that use SATA but are strictly mail servers.

Has anyone had this issue? any ideas appreciated.

Thanks,
Mark